DALLAS (CBS 11 NEWS) – CBS 11 News has learned the Dallas Police Department has finished its investigation into the shooting of a mentally ill man on October 14.

A DPD report stated that Bobby Gerald Bennett lunged at the officers with a knife, but a neighbor’s home security camera told a different story. The video is gripping. It shows Dallas police officers shooting a man whose arms appear to be at his side.

Authorities were called to Bennett’s home by his mother, who reportedly told them her son was off his medication and had a knife. Responding officers said they felt threatened.

“As a council member, I’m very, very concerned,” said Dallas Mayor Pro Tem Tennell Atkins, who wants to reserve judgment until he sees all of the video; so far he has seen only what local TV stations have broadcast. “It [the shooting] was in my district. I’m trying to let the process work through it and the investigation.”

Bennett, 52, was originally charged with Assault on a Public Servant, but Chief David Brown ordered those charges dropped. Councilman Scott Griggs says he was stunned by the video. “Absolutely, everyone is. And that’s why we need to move on this as quickly as possible.” He adds, “We need to get to the bottom of it; we need to get to the bottom of it yesterday. So I look forward to getting a final resolution for this.”

It is Chief Brown’s responsibility to investigate the incident, take action if needed, and report findings to the city manager, except there’s only an interim manager right now. “We all have an interest in getting this resolved and finding out who’s responsible,” said Griggs.

In a prepared statement Dallas Mayor Mike Rawlings said, “I have watched the surveillance video of Mr. Bennett’s shooting and found it disturbing. Clearly this is a serious issue. Interim City Manager A.C. Gonzalez has briefed me about the process involved. I’m confident that the Dallas Police Department will move forward with its criminal investigation into this incident in an appropriate and expedient fashion.”

Other council members, like Philip Kingston, agree. “I don’t want to condemn anybody before we get all the facts in; everybody, including Dallas police officers, are entitled to due process. Obviously it looks terrible…”

But Councilman Kingston believes police internal investigations are even-handed and is confident this one will be open and transparent.

Sources tell CBS 11 News officer Spencer was interviewed by internal affairs Tuesday and this morning was called in to review their findings. Those are often the steps that occur before the findings are sent to the chief.

Some activists have urged the FBI to investigate the issue for possible Civil Rights violations, but the agency will not confirm or deny there’s one underway.

The disciplinary hearing for the officers is scheduled for October 24, at 10 a.m.